MacBook - charger being weird not charging

well my bros charger is being weird. its a magsafe charger that came with the laptop and is using the 3 pronged plug. when you plug it to the outlet in one side has green light lit and the other has both so it turns like yellow orangy even if it isnt plugged into the laptop. it doesnt charge either but it just runs on the charger power. what shall i do?